Which of the following provides both energy and fertilizer?

Which plant is important from an economic and sanitation perspective in rural areas?

Which of the following gases is primarily produced by the action of anaerobic bacteria on sewage?

During biogas formation,which one of the following processes is $NOT$ involved in the anaerobic digestion of slurry?

Mohan was writing a report on the benefits of biogas:
$i$. It is cheap and safe
$ii$. Can be used for cooking
$iii$. Can be transported easily
$iv$. Causes pollution
Which one of the above statements has been reported incorrectly?

Cow dung is appropriately used as